New Mars Forums

Maybe I could add a few things.

Firstly, the “Pegasus”  space launch vehicle (SLV) was developed by a company called Orbital Sciences Corporation in the mid-to-late 1980’s. The first successful launch was in 1990. It was designed from the outset as a vehicle to put spacecraft into space, and is still operated by OSC to this day. Customers (such as NASA) pay OSC to launch their spacecraft into orbit in the same manner as customers pay other companies such as International Launch Services, Lockheed-Martin, and Arianespace to put their spacecraft into space.  From 1990 through to 1996 (the period in question from the HETE case sighted), the Pegasus had an 80% success rate in 10 launches to date. Not a great success rate, but not a disaster for the first 10 launches Development problems are to be expected to some degree (and essentially the vehicle was still in development at that time). An 80% rate for a mature SLV program would be considered not very good. As a comparison, the Delta 2 program (a very mature SLV program) had a 97% success rate from 1989 through to 1998 in 67 launches. Currently, the Pegasus success rate is 91%, a little short of the 95-98% success rate of launchers generally considered very successful.

Secondly, other than having the same method of propulsion (solid rocket motors), Pegasus has no relationship to the “Polaris” and its follow-on “Poseidon” sea-launched ballistic missiles (SLBM) that I believe that you are confusing the Pegasus with. These missiles were designed as weapons of war, intended to throw thermonuclear warheads many thousands of kilometers in a sub-orbital trajectory to targets in the Soviet Union and East Bloc.  Polaris was designed in the late 50’s and early 60’s, and it’s replacement Poseidon in the late 60’s and early 70’s. Poseidon was retired and replaced by the “Trident” SLBM many years ago. If any of these missiles are being used in anything but the occasional reliability test, it literally means that the end of the world is coming in 30 minutes or less.

Thirdly, comparing the Pegasus with the Space Transportation System (STS) (commonly known as the “Space Shuttle”) is unfair in terms of successfully launching things into space.  Despite all the badmouthing that the Shuttle has received in the past few years, it is without exception one of the most successful SLV’s ever developed and flown in quantity, with a launch success rate in excess of 99%. The reason for the Shuttle’s excellent launch success rate is singular: it is a crewed vehicle that requires a “man-rating”. “Man-rating” is a much more stringent reliability requirement than for regular SLV’s for obvious safety reasons.  The Shuttle also has one other need for extreme launch reliability: it has no escape system for the crew in the event of a catastrophic launch failure.

Only a very small handful of SLV’s have 100% launch success ratings (such as the Saturn family of SLV’s). These vehicles were however flown only a very few number of times, so they cannot be compared to a mature family of SLV’s such as STS, Delta, Semyorka, Proton, or Ariane – all with over 100 launches per family. The only mature launch vehicle with a perfect record is the “Altas 2”, which was retired a few weeks ago with 68 launches.

Lastly, your general observations concerning “better, faster, cheaper” missions are spot on – but do not go far enough. Spacecraft  projects of this class (often called “Discovery” class missions by NASA) are of the low budget (in terms of spaceflight) variety.  The spacecraft often are built with off-the-shelf hardware, have a relatively small project staff compliment, and relatively short development times. Project costs are usually capped at $150 million or less. This usually means less redundancy (read reliability) in the spacecraft, shorter missions, and very narrowly focused objectives. Often, one of the largest single costs to any mission is the launch costs, so in this class of mission the launch costs are kept to an absolute minimum as well as the other aspects. This is done by selecting as small a launch vehicle as possible, therefore dictating as small a spacecraft as is possible to carry out the mission (HETE=124kg). The point that I’m trying to illustrate here is that these types of missions are inherently filled with more risk than other missions. This is not true with just the launch phase, but rather the whole mission.

The question you need to ask is if “better, faster, cheaper” Discovery class missions are worth it.  The launch vehicle itself is brand new.

This spacecraft was originally to have been the 2002 Mars Surveyor Lander.

The Landers of the Mars Surveyor Program were all of the same basic size, shape, design, and mission operations. They were part of NASA chief (at the time) Dan Goldin’s “Better, Faster, Cheaper” philosophy that he and his people were imposing on the agency. Only one Lander from the Mars Surveyor program was ever launched –  renamed the Mars Polar Landersome months prior to its launch. It crashed while attempting to land on Mars. The loss of this and another Mars Surveyor spacecraft (the Mars Climate Orbiter) at approximately the same time precipitated a program-wide review. In a nutshell, the review determined that the specific cause of failure could not be determined, but as djellison has mentioned in the prior post, there were very serious flaws in the spacecraft’s terminal descent process as it was designed. What the board also found though, was that the “better, faster, cheaper” mantra that the Mars Surveyor program was modeled after was itself very seriously flawed – and was the overriding root cause for the flawed terminal descent process in the first place. While touted at the time as a way of sending more spacecraft to the planets by making them less expensive, the "better, faster, cheaper" idea was taken way too far because of a zeal at the top at NASA to cut budgets. (Dan Goldin at the time would brag about his asking to have the NASA budget CUT, as opposed to increased. He was quoted as saying that if he has been hired a few years earlier than he was, he would have loved to have cancelled Cassini – a program that he despised. He described it as an expensive dinosaur that he dubbed “Battlestar Galactica”). 

Specifically, the Mars Surveyor failure board found that the program staff was understaffed in order to cut costs, and resultantly overworked. The vehicle itself had many areas of little or no redundancy in order to cut costs. A single point failure on the vehicle at many junctures could scuttle the mission. Equipment was not tested as rigorously as in the past to save money. Basically the whole thing was done way too much on the cheap.

The whole lander portion of the Mars Surveyor program was seen as so suspect that the program in it’s current form at the time was cancelled. This was despite the fact that another flight model had been assembled and was being prepared for launch. It was instead put into storage. This is the vehicle that will be taken out of storage, partially rebuilt to fix the flaws where possible, mission operations redesigned, and re-christened as The Mars Phoenix Lander. This is also where the vehicle gets its name – a new bird born out of the ashes of its prior death. 

Not all was lost in the “better, faster, cheaper” debacle however. One lesson learned was just how far to the bone one could cut with planetary exploration before a mission was too much of a risk. Systems miniaturization and standardization were greatly advanced in efforts to save vehicle weight. Standardization of spacecraft operations were developed.

Ulitmatly, a more appropriate medium between “flagship class” planetary missions such as Cassini and “cut to the bone” missions such as Mars Polar Lander was developed. They were called the Mars Exploration Rover. They seem to work pretty well.