There are two editions of the Bluestar crunched out, and one more is now under development:
- INSEA Bluestar (INSEA stands for International Space Exploration Alliance, an "alternate history" to the space race I started working on before founding ACP; more details in the Cyanstar Overview; between INSEA and ACP concepts, Bluestar is Terry's oldest concept at Meadville...but the unsuccessful Greystar development is actually a couple months older.)
- ISTS Bluestar (ISTS for International Space Transportation System, one of After Columbia's original two projects from February 2003, the other being the Sprint Program.)
- Ascent Bluestar
I crunched INSEA Bluestar in late 2004 to early 2005, shortly after Greystar crapped out on its numbers (I may have posted late 2005 for Greystar in the Cyanstar Overview...that would be incorrect and I will try to edit it.) INSEA Bluestar entered service in 1990. In addition to Cyanstar, which was the heritage for Bluestar's Booster stage, the Bluestar had Volkstar (a successful but uneconomical minishuttle that served from 1986 to 1991) and Yellowstar (from 1981 to 1986, this tested full size Bluestar Orbiter configurations by launching them from the 25 tonne lift Lilmax expendable, most similar to the Saturn IB of contemporary history.) Bluestar, as ugly as the numbers turned out, was still feasible for the INSEA universe. The ISTS numbers, which required pre-extant turbine engine technology, failed to attain orbit with a feasible Orbiter dry mass fraction. ISTS Bluestar used the technical capabilities of the Cyanstar booster (which is probably an optimistic basis for the real world as well) and added oxykerosene engines to the Booster. The required Orbiter mass fraction (some 16% with higher than SSME performance oxyhydrogen) from the resulting 1500m/s staging point is not feasible.
INSEA Bluestar entered service in 1990, burying the Cyanstar with a tenfold reduction in LEO cost/kg ascent costs. At entry into commercial operations in 1992 (some commercial flights in 1991 were made subsidized and with limited free insurance from INSEA), a flight charter cost $2.5 million and lifted 8000kg. By 1994, it was down to $2 million. Today (in 2006), Bluestar Series II has come out and lifts up to 10000kg in tanker configurations for $1.5 million. These seemingly $150 to $250/kg numbers are not quite as rosy as their first impression gives. Bluestar's payloads and dunnage have to be extensively qualified for flight on the $800mln combined Bluestar vehicle with it's four crew members (two in the Booster, two in the Orbiter; up to two more can be carried for EVA and Space Crane support operations.) This lead to a pattern of mass produced/mass derived payload bus hardware...which was conducive to Bluestar's main market: phone satellites...in the INSEA universe today, there would be no cellular phones...period.
Also, these prices are a la carte, and do not include dunnage, deployment, and processing services, which took until about 1996 to really catch up. One of the more exotic ones was the growth of a family of upper stages and later reusable space tugs, to support the geosynchronous market. Hazardous processing was moved to space stations, making payload qualification for ascent on Bluestar a whole lot easier. Between fabrication cost savings, which hurt performance of the satellite, and the cost savings incurred directly and indirectly from Bluestar, I estimated geostationary communications would cost about half of reality's today, about $500,000 per transponder-year. These transponders would offer about 50% greater EIRP performance and more flexibility (satellite lifespans of 10 years vs. reality's 15 allow more frequent upgrades...but require also more frequent replacement.)
INSEA Bluestar Booster:
A low wing delta with high bypass ramfans (turbofan bypass shuts down to allow the bypass afterburner to operate as a straight ramjet) and oxykerosene rocketry (two engines, two motors per engine for a total of four nozzles.) It is equipped with Kreuger flaps and zap-flap like extensions on the elevons, allowing lower landing alphas and shortening of the landing gear.
800,000kg total (ramp weight)
150,000kg ascent fuel for airbreathing engines
130,000kg ascent propellant for oxykerosene climbout rockets
320,000kg everything else (operational empty weight)
$500mln purchase cost
INSEA Bluestar Orbiter:
Alumina protected HL-10 based lifting body; composite integral hydrogen tankage dominates the structure. Uses high performance two part nozzle oxyhydrogen engines similar in thrust to the J-2, but similar in Isp to the SSME (actually it gets 475sec as it operates in a vacuum.) The wing loading is reduced so the Orbiter does not require columbium or RCC on its leading edges. The L/D is crappier than on Shuttle Orbiter, leading to a 25deg glideslope; landing speed is about 140kt vs. Shuttle's 200.
200,000kg total (staging mass)
160,000kg ascent propellant for oxyhydrogen main propulsion
2,000kg orbital maneuvering propellant (tetroxide/UDMH for Mk.1, oxymethane for Mk. 2)
30,000kg everything else (entry mass)
$280mln purchase cost
The 40,000kg Bluedot expendable upper stage was intended to replace the Orbiter. It was a failure, and I had decided that it was when I first thought of it. The Bluestar Booster was designed around the original Orbiter's aerodynamics and structural interface. In order to be cost effective, Bluedot had to be simpler. In early 1994, a Bluedot failed to stage properly, and blew up shortly after staging. The booster crew was somewhat shaken up, but the booster and crew were alright. After consideration of Bluedot's threat to the booster and crew concluded that it was safe enough to continue testing Bluedot, another attempt was made late in the year. The Bluedot stage experienced an unexpected boundary layer transition through the transonic portion of the climb and exploded on the booster's back. Both booster crew members were killed. Fearing a potential problem commen to the Bluedot and Bluestar Orbiter or Booster, the fully reusable Bluestar system was stood down for six months, devastating the commercial market.
After determining the fullly reusable system was safe, with the help of four test flights, Bluestar commercial services were resumed in mid 1995. Bluedot was determined to be far to expensive to operate safely, approaching the competing Lilmax in cost/kg...the expendable it was supposed to replace. Bluedot was cancelled in 1996 after three test flights (one success in addition to the two above failures.)
A final note on INSEA Bluestar is that it was the first aircraft in the INSEA universe to require the pilots to get a type certificate "learner's permit" in the simulator before they were allowed to take the controls of a real one.
ISTS Bluestar (the "real" one) is very similar to the Bristol SpaceBus at http://www.bristolspaceplanes.com/projects/spacebus.shtml
Therefore, after ISTS numbers starting coming back saying, translated into layman's English, "uh, you're joking, right?" I did a check of SpaceBus (the concept that gave me confidence the Saenger II type runway operated spaceplane was reusable) and found that it was 400m/s short of being able to make LEO with fairly optimistic assumptions about the rocketry Isp. Dang.
This brings us to Ascent Bluestar:
Essentially, we are stuck with ISTS Bluestar level propulsion performance with the Booster, but there are a number of things that can be done to the Orbiter that can make it feasible without sacrificing reusability...the downside is that it needs to sacrifice runway operations.
The booster is essentially the same as the ISTS Booster, reshaped to take whatever new shape the Orbiter winds up with. Because the Bluestar booster will still use airbreathing engines and wings for ascent lift, as well as wheel landing gear, they can't be removed without leading essentially back to Shuttle Phase B...one of the worst developmental concept disasters in history. (the existing Shuttle is quite a bit better, but still pretty bad.) The most onerous components to the Shuttle's performance are its wings's, landing gear, and other hardware and decisions made to support gliding runway landing. The answer is simply to drop these items from the Bluestar orbiter and use a more ballistic method of recovery:
The front-running Bluestar orbiter is now a big, unpiloted Sprint-like gumdrop...and the jury is still out on most of its details...especially since I haven't figured out how to get the girth of this thing to fit in a sleek Concorde-like booster. The "Phase B" style approach of pad operated full reusability can be approached totally sans runway by using Greenstar's reusable first stage blocks under Ascent Bluestar's new gumdrop Orbiter, probably four blocks in a square arrangement.
So, as you can see, Bluestar, and with it the cost optimal fully reusable vehicle is not-even-close-to-literally up in the air. The limbo will probably last the better part of a year, as Mars Challenger, Sprint, and Greenstar are all higher priority projects right now...not least because it turned out full reusability was such a pain.