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Atlas V Soars,
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LOCKHEED MARTIN |
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The 191-ft. Atlas V
EELV, surrounded by 340-ft. lightning protection towers, lifts off from new
"clean pad" facilities on Complex 41 at Cape Canaveral. |
The Atlas V, flying an ILS/Eutelsat commercial mission, lifted off from new Launch Complex 41 facilities on 860,000 lb. of thrust from its Russian Energomash RD-180 oxygen/kerosene engine.
THE 191-FT. EELV MARKED the first new unmanned heavy booster design launched from radically new pad facilities at the Cape since the Saturn V of the late 1960s.
"This is a tremendous accomplishment for the Lockheed Martin and Air Force Team," said Air Force Undersecretary Peter B. Teets. The flight "has increased significance due to the war on terrorism [and] our space assets are critical to the war," Teets told Aviation Week & Space Technology. Combined with its Boeing Delta IV competitor, the EELV program has given the U.S. new assured access to space, Teets said.
For accepting the inherent risk of a first flight, Eutelsat paid well below the $75-million catalogue price for an Atlas V 400 to launch its $120-million Alcatel Hot Bird 6 satcom.
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CARLTON BAILIE |
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The vehicle's
twin-nozzle Russian RD-180 engine was at 100% throttle and 860,000 lb.
thrust to propel the 737,000-lb. vehicle off the pad. |
.jpg)
The mission also validated major new ground infrastructure including an Atlas V "clean pad" concept and Spaceflight Operations Center (ASOC) with an impressive new Launch Operations Center and Customer Support Facility. The ASOC alone takes the place of 13 previous Atlas facilities--saving site and manpower costs ( AW&ST Dec. 10, 2001, p. 63).
But the crimson rocket plume from this first mission threatens to be matched by the red ink in Lockheed Martin's Atlas V program unless the company can convince USAF to provide it with $100-150 million extra per year to offset the depressed market, just as EELV operations begin.
"If we don't get that funding, we are going to be losing a whole lot of money here," said a senior Lockheed Martin manager.
Boeing has asked USAF for the same financial help (see p. 24).
As with Boeing, the Air Force contributed $500 million to Lockheed Martin's $1-billion investment in the Atlas V.
The shared government/commercial EELV program has pioneered a new business relationship between the Air Force and its launch contractors where USAF is an investor in the commercial effort to serve both military and commercial users (see p. 23).
While Defense benefits are clear, the current depressed satcom market and booster overcapacity has undercut the commercial economics on which the EELV program is partially based.
Lockheed Martin's business case was set on launching 19 Atlas Vs per year. It dropped that to 12, eight and now six per year, due to the flat commercial market and because Boeing won 21 initial defense payloads and Lockheed Martin seven. The military contracts are worth $500 million to Lockheed Martin and $1.5 billion for Boeing.
A second competition for about four payloads is expected next year.
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CARLTON BAILIE |
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The Atlas V was rolled
to Complex 41 a day before launch on its 700-ton, 185-ft.-tall
mobile-launcher platform, pushed by two yellow "trackmobile"
tugs. |
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If Lockheed Martin "knew then what it knows now" it would have delayed fielding the entire Atlas V 400- and larger 500-series vehicles simultaneously," said John Karas, vice president for Atlas V development. And it would have slowed spending $500 million on new Pad 41 facilities--instead launching initial Atlas Vs off the existing two Atlas pads at Complex 36 here. Those pads are also booked with 14 smaller Atlas IIs and Atlas IIIs through 2005.
The Atlas V 400 series has a geosynchronous transfer orbit (GTO) payload capability of 11,000-16,843 lb. depending upon whether up to three solid boosters are used.
Likewise, Lockheed Martin believes developing the Atlas V itself remains a good bet, because satellite payloads continue to grow in size beyond the 5-ton capability of the Atlas III that introduced the Russian RD-180 engine. Also unlike Arianespace with the Ariane 5, Lockheed Martin can better tailor the Atlas V capabilities--and cost--to individual payloads.
By evolving the Atlas V from older versions, using lean manufacturing and other techniques, the Denver-based Lockheed Martin production team has designed out about 80% single-point failures and cut assembly time by 70%.
Up to five more Atlas Vs are to be launched here through 2003. And satcom operators have signed 30 firm options for the new launcher, said Mark Albrecht, who heads International Launch services. The launch is "enormously significant" to both military and commercial users, Albrecht said.
ILS markets the Atlas and Russian Proton in mutually supporting roles and an ILS Proton launched the Echostar 8 spacecraft from Baikonur just 6 hr. after the Atlas V launched Hot Bird 6.
ILS believes the current global satcom launch market is holding at 20-25 per year with most of those in the 4-6-ton class the Atlas V was sized for.
The Atlas V "looks like rockets have always looked, but if you start getting into the details it is fundamentally new," said USAF Col. Sue Mashiko, who directs the Air Force portion of the EELV program
The flightmarked the first time the Russian RD-180 had been launched integrated with the Atlas V common core booster and stretched Centaur with a single Pratt & Whitney RL10 upper-stage engine.
Unlike the previous fragile pressure-stabilized Atlas, the EELV has an iso-grid structurally stabilized first stage, manufactured from the start to be the core for all of the Atlas V variants.
More than 60 subcontractors and 650 personnel worked for three years here to develop the new launch infrastructure.
The Atlas Vs will eventually spend less than a day on the pad prior to liftoffthanks to the new 293-ft.-tall Vertical Integration Facility (VIF) that supports vehicle stacking and checkout in a protected environment. But to allow for extra margin on this first flight, the Atlas V was rolled to Pad 41 a day early.
Overall, an Atlas V 400 is designed to be checked out and launched in an 18- day flow--10-12 days faster than an Atlas IIAS or Atlas III--saving time and money.
The new 700-ton, 185-ft. tall Mobile Launcher Platform (MLP) carrying the rocket was pushed out of the VIF by two yellow diesel-powered "trackmobile" tugs early Aug. 20. Key avionics and cooling system rail cars accompanied the stack on the 1,800-ft. move to the pad.
Once there, large mechanical autocouplers--multifunctional propellant and electrical umbilicals--were automatically connected to the MLP. The automated umbilicals were pioneered originally by the Russians and save substantial manual connections and checks--also a cost-saving feature.
The 107 x 1.5-ft.-dia. common core first stage was then fueled with 15,000 gal. of RP-1 and the vehicle left overnight before 30,000 gal. of liquid oxygen were added to the first stage on launch day.
The 580-min. countdown was managed in the new control center 4 mi. from the pad. In addition to their own computer displays, controllers could monitor varied data and views on a 360-sq.-ft. wall-mounted rear protection system--the largest of its type in the U.S.
The launch window for the flight was 89 min., but a lack of weather factors and a smooth countdown allowed controllers to proceed through cryogenic loading on the core vehicle and Centaur until a planned 10-min. hold at T-4 min. Once out of the hold, the new Atlas launch control software counted down smoothly until RP-1 valves were opened at T-11 sec. and the final engine start command issued at T-2.7 sec.
The Atlas V has more health management avionics than any previous U.S. booster. A split second before the 6:05 p.m. EST liftoff, engine- and vehicle-guidance computers made final "go/no-go" checks on critical parameters with the engine at 100% thrust. Seeing no problems, the computers fired three large hold-down bolts and released a wind damper separation system high on the rocket.
At the same time, 120,000 gal. of water were discharged to cool the launch platform and an additional 17,500 gal. of water were fired directly into the rocket plume to protect the launcher and pad from acoustic damage.
The RD-180 burns oxygen rich and generates 40,000 mph. of equivalent wind pressure in the pad's flame ducts.
At liftoff, the Atlas V weighed 737,547 lb.--125 tons heavier than the Atlas III. With only a 1.2 thrust-to-weight ratio, the heavy vehicle climbed slowly taking an agonizing 11 sec. to clear its umbilical tower.
Once momentum had been established 4 sec. into the flight, the engine was throttled down slightly to 99%. At 17 sec. and 800 ft. altitude the RD-180 was gimbaled to begin the vehicle's pitch and roll program.
At 100 sec. just after passing the critical Max-Q point, the engine was throttled down again to 95%. As propellant was depleted and the rate of acceleration increased, thrust was then modulated to hold a maximum of 5gs for Hot Bird payload structural limits. About 10 sec. before cutoff the engine was throttled further to reduce loads to 4.6gs to properly condition the oxygen/hydrogen propellants in the Centaur upper stage for its ignition a few seconds later.
At 4 min.--when propellant sensors detected the imminent depletion of oxygen and RP-1--the vehicle's computer rapidly throttled the engine down to 47% thrust. It then commanded cutoff and stage separation at 60-naut.-mi. altitude with the vehicle flying 11,000 mph.
An external camera on the Centaur imaged the shutdown and firing of eight small separation rockets as the stage fell away.
At separation a second camera on the Centaur observed the crank-down of the RL10's extendible nozzle and the ignition of the first of two RL10 firings. This was immediately followed by the separation of the Atlas nose shroud.
After firing 11 min., the RL10 shut down and the vehicle coasted across the Atlantic in a parking orbit. The Pratt engine was reignited off the west coast of Africa for 4 min. to inject Hot Bird 6 into the planned 170 X 24,764-naut.-mi.-transfer orbit. The 8,600-lb. satellite was separated from the Centaur over southern Africa 31 min. after liftoff.
The next Atlas V is set for launch in December carrying a Telesat Canada spacecraft, although as many as three customers have shown interest in riding the second mission. The third flight in early 2003 is planned to be the Rainbow direct broadcast satellite.
© August 26, 2002 The McGraw-Hill Companies Inc.
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