Chair Force Engineer

Thursday, August 30, 2007

Build your own Ares V

Since the dawn of the space age, plastic models of real and fictional spaceships have been one way that enthusiasts expressed their excitement for the bold new endeavor of spaceflight. Rick Husband, commander of Columbia's last mission, admitted that building the Revell Mercury & Gemini kits only increased his desire to be an astronaut.

While plastic models aren't as popular during the new moon race as they were during the original one, there is still a sizable community of serious builders (including the real-space modelers, an under-represented segment of the hobby.) Kits of the next-generation spacecraft are being issued, albeit in small quantities and marketed towards serious hobbyists instead of the mass market. Realspace Models recently did a kit of the Ares I, and Fantastic Plastic has an Orion kit for sale.

Along similar lines, it is possible to build a 1/144 scale model of the Ares V, using mostly the components from existing Saturn V and Shuttle kits. The Saturn V models are produced by Airfix and Monogram, while the shuttle has been kitted by Revell, Airfix & Minicraft (formerly Entex.) For this project, I would recommend using the Monogram Saturn V and Revell Shuttle, because both kits are relatively easy to find, for very reasonable prices. The Monogram Saturn can be found on eBay, while the Revell Shuttle was recently re-released, and can be found at Hobby Lobby and local hobby shops.

Building the Ares V core
In studying the artists' concepts of Ares V, it appears that the Ares v core is almost as long as the Saturn V's first two stages, plus the interstage connecting the two. The diameter of the Saturn V and Ares V is the same, so this is a pretty easy part to fabricate. Simply glue the S-IC, interstage, and S-II together. The corrugated sections on the tube will probably need to be sanded off, because most of them are in different locations between the two rockets. The corrugations on the Monogram kit aren't very good to begin with. They can be replaced with corrugated plastic sheet, which can be found in the railroad section of well-stocked hobby shops. Several detail pieces from the Shuttle ET can also be used to detail the Ares V model, including the SRB attach struts and the LOX feed line.

The thrust structure and engines can be a bit of a problem.The Saturn V had a cylindrical aft end with fairings over the outer engines. While Ares V has engine fairings (albeit smaller ones,) the structure itself is tapered. While it might look passable to simply reuse the aft end of the Saturn V for this model (minus fins,) it would look more convincing to roll the taper and the fairings from thin plastic sheet. Finding a source for the RS-68 engines will also be tricky, but it might be possible to cut them down from the bigger F-1's on the Saturn V.

Stretching the SRB's
Using the standard SRB's from the shuttle kit, how can the 5-Segment SRB's be built? My solution is to cut the SRB where the nose cap meets the top of the upper segment. Then, using an Alumilite casting kit (or a suitable alternative,) make a mold of the upper segment and cast a new one in resin. With the fifth segment glued in place and the nose cap reattached, you've got a perfect 5-segment SRB (except for the new nozzle, which has yet to be revealed.)

Earth Departure Stage
Because the EDS is the same diameter as the shuttle ET, this will make the starting point of the model's upper stage. Remove the LOX tank and the aft dome from the tank with a razor saw. The corrugated portion of the ET will form the aft end of the EDS. If you're using the Revell shuttle's ET, remember to remove the incorrect raised bands on the surface of the ET.

Fabricating the bi-conic nose fairing of the EDS is tricky but not impossible. One solution is to take the LOX tank from the shuttle ET, glue it together, and reinforce the walls with epoxy. Mounting the piece on a lathe, it is possible to file it to the perfect biconvex shape.

The final details come from the Saturn V kit. The adapter between the Ares V core and EDS can be cut down from the adapter between the S-II and S-IVB. If the model is displayed with the stages apart (or if you make your EDS removable,) simply add a plastic bulkhead to the aft end of the EDS and use the J-2 from the Saturn V's S-IVB.

The project I've outlined above should only be attempted by the serious craftsman, and it's not for the feint of heart. It should also be remembered that the completed model is a depiction of Ares V as it appears in today's concept artwork, rather than a realistic model of what Ares V will look like in 2018. The real Ares V will undoubtedly change between now and when it finally flies, if it's ever built to begin with. If done well, the completed model will be a conversation piece and a majestic reminder of the Vision for Space Exploration.

By now, the only question is what should be done with the leftover pieces from this kit-bashing adventure. There should be a complete set of parts for a shuttle orbiter and S-IVB, sitting in their boxes. Perhaps a speculative model depicting the shuttle docking to Skylab should be your next project after finishing the Ares V!

Sunday, August 26, 2007

Soldier of Misfortune

I spent the past week in "Combat Skills Training." Seeing as how I will never be deployed, I considered the class a waste of my time. At the same time, every American should have to go through the training, to get a glimpse of what the average soldier in the Area of Responsibility has to go through.

The worst part of the training was going through the obstacle course on the second day. Imagine a quarter-mile loop consisting of running between barricades while taking simulated fire, crawling through the brambles, ducking/diving/running during the obstacles, and wearing a combat helmet and flak vest. Colored smoke obscured the course, and almost certainly increased my cancer risk when I inhaled it. It was rough, and I was drenched in sweat and grime by the end. Not to mention my knees getting banged and torn up, because AFRL is too under-equipped to issue kneepads to everybody.

The "Convoy Operations" lesson was another eye-opener. It seems like there are a lot of smart procedures that are designed to protect your people from IED attack. At the same time, a lot of guys get lazy or sloppy, and don't put these practices into effect. The result is a lot of GI's getting killed or maimed because people forgot to implement their training.

While the guys who are deployed certainly have better equipment than stateside weenies do, I'm still overwhelmed by their ability to put up with such physical and mental exertion on a daily basis for up to 15 months. It should go without saying that the American Soldier/Marine is the best-trained, most professional, and most motivated fighting man in the entire world.

Friday, August 24, 2007


Last night, I had the most horrible nightmare. I am not making this up. I remember my dreams far more often than I probably should (perhaps it's part of the sleep disorder that I'm being checked out for.)

I dreamed that STS-118 was lost on re-entry, and the shuttle program came to an immediate end. NASA had announced that the crew's remains hadn't been found, although there was no chance they could have survived the breakup at 114,000 feet. I recall being confused if the orbiter was Atlantis or Endeavour, because logic doesn't seem to work in dreams (with the functions from the non-dreaming half of the brain not being used.) I also recall comparing the Endeavour's loss to a similar event in Buzz Aldrin's novel Encounter With Tiber.

In the next part of the nightmare, I turn into a staunch Stick supporter. I call for development of Ares I at an accelerated pace, because "no astronaut should have to die in the shuttle again." Apparently, in the land of dreams, the "Safe Simple Soon" mantra is still true.

I don't attach any particular significance to dreams. I don't view them as being anything more than the brain's way of releasing the stored anxieties accumulated during the day. I still find it funny that I would have a nightmare about the recent successes of STS-118, although the bad memories of Columbia will always haunt me. I think the funniest part of this nightmare is how dorky I am. My becoming a strong proponent of The Stick is the stuff that my nightmares are made of.

Tuesday, August 21, 2007

Mission Complete

The successful completion of the STS-118 mission is a major emotional milestone for NASA and for all manned spaceflight programs. It brings closure to many of the unfulfilled ambitions that were left open due to the twin disasters that have unfortunately left an indelible mark on the Space Shuttle program.

--It was the first successful flight of an educator-astronaut, Barbara Morgan. She watched in agony as her friend throughout training, Christa McAuliffe, perished in the Challenger disaster.
--It was the first mission for Endeavour since STS-113 in December 2002 (The last successful mission before Columbia was lost, and the last launch I witnessed in person.)
--STS-118 was the last mission that was officially manifested for Columbia prior to the orbiter's destruction.
--STS-118's pilot, Charles Hobaugh, was the CAPCOM for STS-107, and was the source for the desperate calls of "Columbia, Houston. Comm check."

Hopefully the completed mission will be a cathartic event that helps NASA to finish the shuttle program safely and transition to Orion smoothly. It should inspire all of us to bounce back from our mistakes and continue our pursuits. On a personal level, the successful flight of an educator-astronaut gives me hope that, even if I pursue a career teaching high school, the space program can still be a part of my life.

Saturday, August 18, 2007

From Expendables to Spaceships

Sometimes I wonder if I will ever see mankind build a true, reusable spaceship that replaces at least some of the expendable rockets that we rely so heavily upon. The problem is that there just aren't enough satellites in need of launch to justify the high development costs of a Reusable Launch Vehicle.

Therein lies the chicken-and-egg dilemma of RLV's. Nobody will commit the money to developing one, because the number of payloads means you'll never recoup your original investment. But if an RLV already existed, the number of payloads would possibly (but not certainly) increase as a result of having cheap space access.

Some RLV proponents might argue that the government should subsidize RLV development, or perhaps launch a satellite program that would require an RLV to complete it. I've often joked that NASA should build a gigantic orbiting sign that reads "No Fat Chicks." Such a sign would be miles across and could be read from earth. It would go into sun-sync orbit, so all the world's people could enjoy it at a predictable time of day.

Space tourism does give us hope that the aforementioned "egg" will be cracked. By opening the space frontier to thrill-seekers, you can dramatically increase the number of "payloads" that can be flown. The question is whether this potential market is big enough to justify further RLV development. Many people are risking their fortunes on the belief that it is. I suspect that suborbital tourism will be a thriving market within the next decade, but I also see orbital tourism being constrained by excessive launch costs. The path to the stars will probably begin with a sizable number of people paying a reasonable amount of money to take suborbital spaceflights. Using the profits from suborbital tourism, the suborbital vehicles can be further developed into orbital spacecraft. Once we have moved away from the "capsule on an expendable" paradigm, the orbital tourism market will open up.

Thanks to the space shuttle program, we have learned quite a bit about what will be required for a successful RLV. The shuttle was designed on the idea that it would have to replace virtually every US launch vehicle. It was designed as a large RLV with a large payload bay in order to accommodate a wide variety of payloads. Unfortunately, shuttle would never meet the high launch rates that were required to replace the other US launch vehicles. Designed for approximately 26 missions a year (it will fly every two weeks, or so we were told,) we learned that nine flights per year was pushing things to the point where operations became dangerous.

I have often thought about how big an RLV should be in order to be commercially viable. Should it be sized to compete with Soyuz, or maybe Proton? I suspect that even if the RLV replaced the world's most popular launch vehicles, it would still be a losing proposition at today's flight rates.

One idea I've been kicking around has been a single-stage, orbital RLV for launching nanosats. While single-stage rockets are horribly inefficient, they are much simpler from an operational point of view. Because this hypothetical RLV would only be carrying nanosats, it would be well within the range of what's technically possible. Because there are so many engineering schools in the world, the potential customers for this single-stage nanosat launcher would be numerous. This RLV would definitely open up the space frontier to universities who previously had no ability to afford space launch services.

Sunday, August 12, 2007

TPS Report

Tile damage on shuttle Endeavour looks much more serious than initially thought. Recent scans of the shuttle's underside show that two tiles have been completely gouged through to the felt layer underneath.

Depending on the tile location, scars of this depth could prove fatal. On STS-27, the mission was saved by a heavy plate being located underneath the damaged tiles. In our current situation, the damaged tiles lie below wing structural members near the right landing gear.

NASA's current options include flying the shuttle back as-is, repairing it and flying it back, or rescue of the crew by another orbiter, accompanied by an unmanned return of the repaired Endeavour. Of these, I think that doing no repairs is probably out of the question. Even if NASA was able to return the shuttle safely, the perceived dangers of doing so would call into question the safety culture that was supposed to have improved after the loss of Columbia.

I also think that a rescue mission is unlikely. While there's supposedly a system for auto-landing a damaged orbiter, I doubt that the agency is very enthusiastic about testing the system during a mission. A rescue mission would also add an additional delay in the ISS completion schedule. Worst-case, a "rescue" mission is a sign to the public that the shuttle program is too dangerous to fly any more missions; it would likely mean the abrupt end of the space shuttle program.

At the same time, NASA has twice exercised the capability to perform minor "repairs" on the shuttle since return-to-flight. While neither the gap filler on STS-114 nor the loose blanket on STS-117 represented a risk to mission safety, they were performed anyway. NASA wants to demonstrate that it will make the additional effort to rule out even tiny threats to astronaut safety. It also wants to show off the repair capabilities that were developed, at considerable expense, in the aftermath of Columbia's loss.

What do I expect to happen? I think that Michael Griffin is going to go on CNN and tell the world that the astronauts are going to repair the damage and bring the shuttle back as scheduled. He's going to express his confidence in the repair techniques that have been developed to fix the thermal protection system. And the astronauts are going to ride the CanadArm extension to the underside of the shuttle, and fill in the gouges with ablative material. With some divine intercession, they'll make it back home in one piece.

Monday, August 06, 2007

It Takes a Carrier Battle Group to Raise a Capsule?

In my last post, I briefly touched on the logistical and fiscal challenges that accompany NASA's impending decision to have Orion make a splashdown recovery. I should not have implied with certainty that such splashdowns will require a carrier battle group.

However, it will take quite a bit of effort and money if NASA wants to duplicate the assets that the US Navy brings to the table. NASA will need a ship equipped with a helipad, medical facilities, tracking radars, and the necessary cranes for hoisting the capsule from the water. It will also need to supply the helicopter and the divers for retrieving the capsule. Perhaps this is a worthwhile investment for NASA. Only time will tell.

I still feel that Orion is operationally disadvantaged now that splashdowns are becoming mandatory. A capsule with airbags could still make a splashdown, but a capsule without airbags would have a very violent landing if it somehow missed its watery target. It will also pose a disadvantage if ISS experiments need to be rushed to a lab upon their return. And, as Rand Simberg points out, the splashdown recovery will probably preclude NASA's goal of reusing each capsule ten times.

Sunday, August 05, 2007

Flags, Footprints, and Splashdowns

In order to fit the lunar-capable Orion spacecraft on the Ares I booster, NASA and Lockheed Martin are cutting a lot of weight. The most recent deletion is the set of airbags that would have enabled Orion landings on terra firma.

So the mismatch between Orion mass and Ares I performance is solved. But what's the price to be paid for this solution? For one thing, an entire carrier battle group will have to be put on notice for each mission, and NASA will have to foot the bill that the US Navy will send its way. If the capsule has to come down in the event of an emergency, the crew had better hope that they don't end up on land by accident; the capsule's lack of airbags and structure will ensure that the astronauts inside will have a very bad day indeed.

Speaking of safety, the change to splashdowns is also allowing NASA and LockMart to bring back storable (but carcinogenic) propellants for the capsule's reaction control system. Hopefully we won't see a repeat of Apollo-Soyuz Test Project, where the Apollo capsule's cabin filled with toxic fumes from the thrusters upon splashdown.

With the costs and operational complexities associated with splashdowns, I think this will be the nail in the coffin for any plans of a moonbase in the 2020 timeframe. I can't foresee launching more than four Orions per year (two to ISS, two to the moon initially) over a sustained period of time if it takes a carrier battle group to retrieve each capsule. Constellation will become just like Apollo: flags and footprints, with little hope of building an infrastructure after the initial sortie missions.

I don't understand why NASA would sacrifice operational flexibility and assume increased operating costs, just so they can avoid admitting that Ares I is a mistake. While the booster may be "safe, simple, and soon," the capsule is sacrificing whatever safety gains are achieved by the booster. I'd prefer that NASA make the capsule as heavy as need be to ensure the safety of the crew, and only then select a booster that can do the job. God forbid that should drive NASA to choose Atlas V Heavy or Jupiter-120.

The Soviets have been landing capsules since 1964, with Voskhod-1. While the US initially chose splashdowns because of the limited capabilities of our early boosters, we should be able to do better by now. Let's leave the splashdowns for turds. Spacecraft should make landings.

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