1/100 Tamiya Space Shuttle

Orbiter Challenger  

by Justin Davenport

--------------------

  20th Anniversary of the loss of Challenger    

 

“CHALLENGER, GO AT THROTTLE UP”

On January 28, 1986 astronauts Dick Scobee, Mike Smith, Ron McNair, Judy Resnik, Ellison Onizuka, Gregory Jarvis, and Christa McAuliffe boarded the astro van and were driven to launch pad 39B. Their flight, STS-51L, had been delayed a few times, including the previous day when a balky crew hatch would not close properly. But this morning dawned bright and clear, though unseasonably cold, and everything looked like it was finally GO for launch.

The Space Shuttle Orbiter Challenger, mounted on its orange external tank and white solid rocket motors, was fueled up and waiting for her crew. STS-51L was the second shuttle mission of 1986, and one which would launch a Tracking and Data Relay Satellite into geosynchronous orbit atop an Inertial Upper Stage mounted in a cradle in Challenger’s payload bay. Also mounted in the payload bay, forward of the TDRS-IUS combination, was a small satellite called Spartan. It would be launched by the shuttle’s Canadian-built robotic arm (RMS) into an orbit near the shuttle, and it would point its ultraviolet telescopes toward Halley’s Comet, which swung close to Earth every 76 years. The Spartan-Halley observations were not possible on earth because the atmosphere blocks ultraviolet rays, and scientists hoped that the UV observations would reveal much about the comet’s nucleus. However, most of the mission’s media coverage was focused on Payload Specialist Christa McAuliffe, who was a schoolteacher in Concord, New Hampshire (Concord High School). NASA had launched its Teacher in Space program after the shuttle became operational, and school teachers throughout America entered their names. NASA winnowed the applicants down to a select few, and Christa McAuliffe was selected with Barbara Morgan as her backup. During the flight, Mrs. McAuliffe would teach a lesson plan from orbit to her students. Excitement was strong among young people and teachers as the flight neared.

The orbiter Challenger flew nine successful missions from 1983 to 1985.  Among other things, Challenger's crews pioneered untethered spacewalks with the Manned Manuevering Unit, repaired the Solar Max satellite, flew the first US woman in space, the first African-American in space, and the first Canadian in space, and also flew several Spacelab missions.

Click on image below to see larger image

Challenger’s liquid-fueled main engines, at the back of the orbiter’s fuselage, ignited on schedule at T-6 seconds, and at T-0 the two solid rocket boosters ignited. Challenger cleared the tower and began its roll program. Everything looked good as Challenger continued her climb toward space. At T+68 seconds, CAPCOM Dick Covey called “Challenger, go at throttle up”. Challenger commander Dick Scobee responded “Roger, go at throttle up”. Three seconds later, Challenger disappeared into a massive orange ball of flame, and the two solid rocket boosters flew out of the cloud. Horrified onlookers began to realize what happened, and mission controllers in Houston began to get data confirming that the vehicle had exploded. At T+116 seconds, Mission Control spokesman Steve Nesbitt said "Flight controllers here are looking very carefully at the situation. Obviously a major malfunction." Air Force and Coast Guard rescue crews began searching for the crew, but the orbiter was not equipped with any ejection seats or rescue capsules as the risk of loss of vehicle was deemed too low to require a heavy and costly crew escape system. Within hours the nation began a period of mourning for the lost crew of Challenger, and tributes to STS-51L’s crew flowed from throughout the country, and around the world. President Reagan addressed the nation and postponed the State of the Union address, scheduled for the evening of January 28th, out of respect for the crew; he ended his address with “we mourn seven heroes”.

Within weeks, pictures and videos of Challenger’s ascent were released that revealed plumes of flame along the joint between the right solid rocket booster and the bottom of the shuttle’s external tank. A puff of smoke had appeared shortly after liftoff in the area of the joint, and data from Mission Control’s computers was also pointing toward a malfunction of the right solid rocket booster. Wreckage from the right SRB, which had been destroyed by range safety officers, had been recovered by late April, and analysis of that wreckage confirmed the cause of the disaster, hot gases leaking past O-rings made brittle by the cold temperatures on launch day. In June, the Rogers Commission released its report outlining the cause of the Challenger disaster and its recommendations to NASA to fix the shuttle fleet before flights resumed in 1988.

I was a freshman in high school when the disaster happened; I remember my teacher breaking in just before math class telling us about the explosion. I had been somewhat interested in space before the disaster hit, and had remembered that one of my teachers in junior high had applied to the Teacher in Space program. After Challenger, I began to read everything I could about the space program, and I looked forward to the day that the shuttle would fly again. And it did, on September 29, 1988. My grandpa and I drove out to Edwards Air Force Base a few days later to watch Discovery’s landing in person. The Space Shuttle program flew safely for 15 years before Columbia, the oldest orbiter in the fleet, broke up on re-entry on February 1, 2003, and during this period of flying the shuttle launched several planetary probes, numerous Spacelab and science missions, several large observatories, including the maligned, then storied Hubble Space Telescope, flights to the Russian Mir space station, and on-orbit assembly of the International Space Station. 2006 is the 20th anniversary of STS-51L’s last flight and also the year that ISS assembly resumes after STS-121 returns the shuttle to flight in May. One of the astronauts scheduled for a future flight to the ISS is Barbara Morgan, Christa McAuliffe’s Teacher in Space backup.

Click on images below to see larger images

THE MODEL

I began this project in August after I finished the Airfix 1/144th scale shuttle stack. I wanted to have something done to mark the 20th anniversary of Challenger, something that would do that fabulous bird justice. I was inspired to build the 1/100th scale Tamiya kit that was beckoning to me in my stash - I wasn‘t in the mood to tackle the 1/72nd kits. I had done the last Tamiya kit as Columbia and sent in an article to Steve with some shots of my model when Columbia went down. Unfortunately, that model has fallen apart, and I figure now that the other Tamiya shuttle in my stash (I bought it after I started work on this one) may well become Columbia. The Tamiya kit is larger than the usual 1/144th scale kits but not as monstrous as the 1/72nd scale orbiters from Revell and Monogram, and it builds into a good representation of the orbiter, particularly the earlier orbiters with extensive white tiles on the wings. (Challenger had these white tiles; Discovery and later orbiters replaced most white tiles with an advanced fabric insulation). I decided to build the Tamiya kit as Challenger, on its landing gear.

Tamiya re-boxed the shuttle kits after the Columbia disaster and re-released them; unfortunately, the decal sheet is very sparse, and so I bought a sheet from JBOT Decals in Canada. This sheet had all the orbiters, including Challenger. The kit does include a decent cockpit and upper crew compartment as well as a payload bay that is a good base for further detailing; its landing gear bays are good by shuttle kit standards. The shape is accurate, although the windshield is not completely right (NO shuttle maker has got it completely accurate), and the tiles are beautifully molded on the wings. However, Tamiya for some reason did not mold the tiles on the tail or the nose and payload bay sections; I pondered what to do about that as I started the build.

Click on images below to see larger images

I started the build by working on the crew compartment. I used Tamiya spray paint - RAF Ocean Gray - for the shuttle cockpit and inner bulkhead. I used scale black for the cockpit coaming and seats as well as the astronauts’ boots. I painted the astronaut figures Polly Azure Blue (STS-51L’s crew - and the crews of all previous shuttle flights - wore flight suits of that color) and Flesh for the faces as well as white for the helmets. I glued Reynolds Wrap foil on the back of the cockpit bulkhead, the payload bay floor, and the aft payload bay bulkhead, then painted the cargo bay elements with Painter’s Touch white primer. I glued the cockpit to the payload bay as per the instructions, then the payload bay into the fuselage. I then decided that I would scribe the black tile areas around the nose and on the tail with my X-acto knife, and leave the white areas on the rest of the nose to later if at all. After the scribing, I finished the basic assembly of the fuselage and wings, and I did a fit check of the payload bay doors. I had thought that I would let them open and close - however, the bird was going to be on its landing gear, and there was an unsightly gap between the payload bay doors and the fuselage sills. So I decided to close the payload bay permanently, which left me with no use for payload bay radiators beautifully painted with Testors Metalizer Stainless Steel. One other thing I had to do that affected me later was that I had to finish the landing gear struts and glue them into the gear bays, then glue the gear bays into the orbiter during the assembly - there was no other way that the gear would attach to the orbiter. So for the entire duration of painting, the bird was sitting on landing gear stalks. During this time, I airbrushed MM Metalizer Gunmetal on the engine bells and finished the engine bay, with tiles carved in to it somewhat roughly but acceptably. Before I started painting, I decided to sand down the raised ridges at four points on the payload bay doors - they are inaccurate and are not on the real orbiter. After much sanding, and some rescribing, I finally got a result I was satisfied with. I used Painter’s Touch white primer to spray the bird, but I kept running into little imperfections, some of which had to do with the sanded area and rescribing around the ridges, and I had become burned out by early October. I needed a break, and so I set the project aside while I got ready for a family trip to Hawaii.

Click on images below to see larger images

Once I got back from Hawaii in early December, I wanted to build again, and I had a Tamiya shuttle and a Matchbox A-4 - half finished - waiting for me. So I got cracking on the shuttle as Christmas neared. I used some Tamiya sandpaper as well as some new Twobobs sanding sticks to get an acceptable base for a gloss white finish, and I got a decent gloss white coat on with a spray can. After drying, I used Tamiya tape to mask off the black areas on the wing leading edges and nose, then sprayed more gloss white to seal in the tape, and I brushed Polly Night Black on those areas. I also used the brush to tackle the underside and got good coverage without ruining my white gear bays - I thought about ways to mask the gear bays but nothing good came to mind, so the spray can was out. After I unmasked the black areas I noted that some areas where the tape was were thicker than other areas - “stepped” in fact. So out came the Tamiya fine grit sandpaper, which solved the issue and blended in the thick areas to an acceptable level. Of course, these new areas looked flat, but that was okay. I just wanted to get the bird done. I decided not to break out the Tamiya clear coat due to the horrid experience I had on the last shuttle project. I also decided that I would not scribe white tiles on the nose or tail or payload bay sills - flat base would represent those areas. I did not feel confident that I could scribe the white tiles without ruining the bird. I finished the black areas on the wing (Challenger’s flap-wing boundary area was all black, unlike the area on the current orbiters) and painted the carbon-carbon areas on the wing leading edge and nose cap Polly Haze Gray. I also finished the tail and the OMS pods at this time, with the umbilical plates at the back painted MM Acryl Brass, and the landing gear, with the tires painted scale black, and just before New Year’s the bird was ready for its decals.

DECAL WOES AND SOLUTIONS

I broke out the JBOT decal sheet and started with the hatch decal. Unfortunately, it broke apart on me when I tried to apply it. I dug out the instructions that came with the decals and said that they were thin and that you could spray on a clear coat before or after the decals are applied. I used Tamiya decals to continue the project - putting on the windshield decal and a few round nozzle decals for the RCS jets in the back. I did some experiments with a can of Vitacal that I had used to make decals for my European AF Rafale a while back, and as matters turned out, three light spray coats of that stuff will make the decals work without cracking them like heavier coats did to test articles. (JBOT had a few spare decals good for that purpose). In short order, I got the rest of the markings done with the exception of a couple of payload bay hinge tile areas which I duplicated with Scale Master black stripe decals. I also had an accident with the NASA worm decal on the right wing and that was lost….so I searched about for alternatives until I found one of my 1/72nd scale Cutting Edge shuttle decal sheets. The CE decal was perfectly sized, whereas the 1/72nd Real Space decals were a hair too small, so I used the CE worm on Challenger’s right wing and it worked great. I also used a Real Space Models “Challenger” decal under the worm, from a sheet that had some 1/100th scale Orbiter name decals, “meatball” logos, and windshield/OMS tiles. (The rest of that sheet had been used on Columbia). This particular sheet is no longer made, so I didn’t bother with the tiled areas on the OMS pods that Challenger had on its final flight (though it did not have on its earlier flights). Real Space Models Challenger decals also went under the windows of the nose section. Once the decals were on I touched up a few areas with Floquil Reefer White and all was set, my bird was done on January 4th. A great way to start the New Year off right!

Click on images below to see larger images

Thanks to Caz Dalton for writing the articles on photography - I made good use of it when putting together my "shuttle in orbit" picture using Paint Shop Pro.

More resources on the Challenger disaster that I made use of:

God bless the crew of STS-51L and all other crews lost in the exploration of space and their families and loved ones.

"Sometimes when we reach for the stars, we fall short, but we must pick ourselves up again and press on despite the pain," he said. "Our nation is indeed fortunate that we can still draw on an immense reservoir of courage, character and fortitude - that we are still blessed with heroes like those of the space shuttle Challenger. Man will continue his conquest of space. To reach out for new goals and ever greater achievements, that is the way we shall commemorate our seven Challenger heroes." - President Reagan, to NASA workers and Challenger astronaut families at the Johnson Space Center. 

Justin

Photos and text © by Justin Davenport