NEW HEAVY LIFTERS FIGHT FOR JOBS
The size and mass of geostationary communications/broadcasting/broadband satellites is increasing sharply over the near term. Thuraya-1’s lift-off mass of 5,108kg might have been the world’s heaviest single payload when it was lofted by Sea Launch on 20/21 October, but its record will not stand for long, writes Chris Bulloch.
Telesat Canada’s Anik-F2, which will weigh-in at 5,900kg when it flies on Ariane 5 in late 2002, currently holds this honour. This would coincidentally put it at the mass limit of the current AR.5 for a dual payload. But by then the ‘Versatile’ version of this booster should be able to put 7,300kg into a GTO orbit. So Anik-F2 could have a companion.
Ariane 5 is just one of at least four new heavy-lift launch vehicles coming to market over the next two or three years, or existing launchers which are having their performance radically enhanced.
At the same time, while payloads may be growing in mass individually, they are not set to grow vastly in number over the next few years. Euroconsult of Paris foresees a sharp decline in the number of geostationary payloads, from 20 missions in total for 2004 to as few as seven the following year. The total will remain below 20 flights per year until 2009, by which year Euroconsult foresees a sudden upsurge to around 29 missions.
This boom-and-bust swing is typical of the cyclical launch business, in which all satellite manufacturers tend to bring new products to market in a similar timeframe: witness the clutch of Ka-band broadband satellites set to launch over the next few years. Everyone is climbing on the same bandwagon at the same time. But modern satellites are built to last – provided all goes well with them – for a minimum of 15 years. So a launch feast will be followed by a long famine.
There has already been one drop-out in the race to develop new heavy-lift expendable launchers with a low specific cost (price per kilogram of payload). US banker Andrew Beal has abandoned his attempt to develop a ‘Big Dumb Booster’, the BA-2, using his own money to devise a low-cost vehicle based on very conventional and indeed old-fashioned technologies. He blames competition from NASA.
Ariane 5: The Ariane 5 evolution programme was approved at the 1995 ESA ministerial-level conference at Toulouse, once it appeared clear that the new vehicle’s basic performance (6,200kg to GTO for a single payload, or 5,900kg for two satellites which would need an additional housing) would soon prove inadequate. Several programmes were in fact brought into being, to be introduced successively into regular production (while at the same time holding production costs down consistently). The initial ‘Evolution’ plan would save weight by using welded rather than bolted solid booster segments, while take-off thrust would be increased by giving the solid boosters 24 tonnes more propellant, for a total of 714t.
Also part of the Evolution programme would be the introduction of the Vulcain II mainstage cryogenic engine (LH2/LOX). This will increase thrust (from 118t to 138t), while the intertank bulkhead between the liquid oxygen and hydrogen compartments would be lowered to increase LOX capacity, since the new engine has a different mixture ratio.
A new storable propellant upper-stage Aestus engine will enter service in late 2001. This ‘Versatile’ engine was originally conceived for flying constellations of LEO satellites, a market that seems to have evaporated for the present. But its flexibility – it can be restarted several times, allowing a total upper stage flight duration of several hours including unpowered ballistic coast phases – will allow launches to a variety of unconventional orbits, including direct insertion into GEO. It will also put 7,300kg into GTO.
Ariane 5 will only make a quantum leap in performance with the AR-5 Plus programme, which will bring cryogenic propulsion to the upper stage. The ESC-A stage (the acronym derives from the French for Cryogenic Upper Stage) will use the HM-7B engine from Ariane 4, but with larger tanks. It will be in service by the end of 2001 and will place two satellites totalling 10 tonnes into GTO, or a single 10.5t payload.
Coming along much later, in 2005, is ESC-B, to feature a brand-new expander cycle engine from SNECMA called Vinci, plus 25t of cryo propellants. This will be restartable up to five times in flight. There was discussion of making this a co-operative project with Pratt & Whitney, but Astrium engineers in Bremen foresaw a decrease in their work share, so ESA turned the project down. The Vinci engine will cost E1.1 billion to develop, making its mass gain (11t dual launch, 12t single payload) a costly achievement.
The Japanese Space Agency: NASDA’s H-IIA launcher was to have made its maiden flight next February. But an accident last July caused NASDA to revise the main-engine turbopump completely. This means the first flight will be unable to launch ESA’s technology demonstrator satellite Artemis as planned in a launch-for-communications access swap deal.
The H-IIA is an improved and allegedly cheaper variant of the H-II, now retired following two failures. It features enhanced versions of the first and second stage cryo engines (HE-7A and LE-5B respectively), plus new-design solid boosters with single-segment casings. But the H-IIA will not get into the Big League until NASDA has completed development of its planned Liquid Rocket Booster; this is actually a near-duplicate of the vehicle’s cryo first stage, but with two HE-7A engines instead of one. Consequently it will exhaust its fuel twice as fast before being jettisoned. Availability date for this version is still unclear.
With one Liquid Booster and two solids, the H-IIA could fly 7.5t to GTO. There are further undated plans for using two LRBs, which would raise lift capacity to 9.5t; this is still short of Ariane 5/ESC-B performance.
Angara/Proton-M: Back in 1993, Russia held a competition to replace the Proton, which had been its only GTO launcher since the late 1960s. Another motive was the desire to escape from dependence on Baikonur, which was the sole base Proton could use. Baikonur is in Kazakhstan, and relations with the Kazakh authorities have not always been tranquil. Also, for use on its own territory (Plestetzk was the favoured site), Russia preferred to rely on non-toxic propellants, such as LOX/kerosene.
First out of the gate will be the Proton-M (with Breeze-M top stage) which will first fly this year with a Russian payload (and with Intelsat 901 next year as its first ILS mission). But Proton-M will remedy none of the objections listed above.
So the winner of the contest was Khrunichev’s Angara proposal, which beat out a scaled-down version of the SL-17 Energia ultra-heavy booster, which flew the former USSR’s space shuttle Buran (just once) back in the late 1980s.
The Angara family of launchers will be based on a “Unified Stage Module” or in other words a Common Core Booster, like the Delta IV. This will fly either alone (as on the Angara 1.1), with a Samara upper stage (Angara 1.2), or in a cluster. The two versions just mentioned are intended as Light/Medium launchers, to replace the Rockot and Cosmos, and will not be handled by ILS, which is otherwise encouraging the Angara project by investing around $70 million (E81.44m) in it in exchange for exclusive marketing rights (outside Russia).
The USMs will all be powered by an Energomash RD-191 engine, which is a single-chambered derivative of the two-chamber RD-180 as used on Atlas III and V. This in turn is descended from the four-chambered RD-170/171 of the Zenit.
Though at present licences for US payloads to fly on Russian launchers are subject to quotas, ILS is convinced that “they will die by the end of this year.” Recent exchanges between presidents Clinton and Putin have contained statements from Khrunichev to the effect that the latter company has “successfully demonstrated its compliance with all trade and technology control requirements and is a fair competitor in the marketplace.”
EELV – Atlas V and Delta IV: These two launchers are Lockheed Martin’s and Boeing’s submissions for the US Air Force’s Evolved Expendable Launch Vehicle programme. This is the US governments third try at reducing launch cost by developing simpler vehicles that are less costly to operate. This time, the government has made two unequal awards to build vehicles that the contractors will be able to exploit commercially as well as for government missions (these will be the only ones for which the designation EELV will be applicable).
Boeing has a significant lead, having received a 1998 award for 19 missions compared with nine to Lockheed Martin. The latter company has now “asked to be relieved” of the need to build an Atlas V pad at Vandenberg Air Force Base in California, to launch just two polar-orbit flights. These now go to Boeing’s Delta IV, for a total of 28 EELV flights from the two contractors. ESA may cry foul at the amount of US government payloads, but should remember that European government payloads invariable go to Ariane, including the nine ATV launches signed up at the Berlin Air Show this past summer.
Atlas: One result of Lockheed Martin’s dropping out from the polar-orbit EELV market is that the Heavy version of the Atlas V with three common-core boosters now seems unlikely ever to be built. Essentially it replaces the Titan IV (only about ten remain in inventory), so this is a further business loss for L-M. The largest Atlas V now planned will have a single liquid booster stage powered by a single two-chamber LOX/kerosene RD-180 engine, flamked by up to five Aerojet solid boosters. The upper stage will be either a single or twin-engined P&W Centaur RL10 cryogenic engine. This vehicle could put 8.2t into GTO. The current Atlas III which made its first flight this May with Eutelsat’s W4 is not quite identical to the Atlas V, but sufficiently similar to have “retired 80% of the risk involved” in the newer launcher. Lockheed Martin plans to cease producing the Atlas III once its successor is up and running. L-M plans to build “at least 100 Atlas Vs”.
Delta IV: This is based on Boeing’s new Common Core Booster, which will carry a new Boeing Rocketdyne RS-68 cryogenic engine delivering 293t thrust. Described as “30 per cent more efficient than LOX/kerosene engines” – which could be read as a criticism of Lockheed Martin’s RD-180 – which itself has a thrust 32 per cent higher than the Rocketdyne engine.
The ‘Medium’ EELV version of Delta IV with an RL10B-2 upper stage taken from the Delta III is complemented by three ‘Medium-Plus’ versions for commercial missions; these have two or four solid strap-ons and either 4m or 5m diameter fairings. Finally there is the Delta IV Heavy version with three coupled Common Core Boosters, which is likely to be reserved for government payloads only.
Sea Launch: As remarked earlier, Boeing affiliate Sea Launch is making “incremental changes” to its launcher to raise its GTO capacity to 5,700kg. But it has no immediate plans to give it a dual launch capability, believing that there will be an adequate supply of customers with large single satellites. Its next payload will be the first XM Radio satellite in December.
Long March: There were reports from the IAF Congress in Rio last month to the effect that China Great Wall was upgrading the performance of is most powerful vehicles, but little detail was available. It is thought unlikely that licences will be forthcoming for launching US-built satellites on Long March, especially if Russian quotas are to be relaxed.
India’s ISRO: This body (or its commercial arm Antrix) hopes to do business with its Geostationary Space Launch Vehicle (GSLV), which has not yet flown. It is set to make its first flight next year, initially orbiting a mere 1,600kg payload to GTO. Future plans involve stretching the GSLV’s capacity to 4t to GTO. ISRO is currently dependent on Russian engines for the cryogenic second stage of GSLV. It should be noted that it is provisionally pricing GTO launches at a cost (not price) of $35-40 million a throw.
GTO Launch capability
| * Masses in kilograms; dual-payload data
given only for Ariane V, other launchers single
payload. Definitions of GTO launch may vary.
|Proton M + Breeze M||