Two major launches happened in early April. One was a swansong launch: the Delta IV Heavy’s last flight. The other was supposed to be the first launch of a new version of the Angara-5 to formally start its operations from the new Vostochny Cosmodrome in far Eastern Russia.
The final ULA-operated Delta IV Heavy lifts off from SLC-37 Cape Canaveral on 9 April 2024. Courtesy: ULA
A swansong launch: the Delta IV Heavy’s last flight
The launch, planned for 28 March, was delayed by nearly two weeks due to a gaseous nitrogen pump failure. A new attempt was made when a Delta IVH-4050H (upgraded version) was launched at 1653 carrying the NRO L-70 mission from Cape Canaveral, Florida, on 9 April. The undisclosed US 353 spacecraft carried on ULA flight is probable Orion 12 or 13 signals intelligence satellite and is designed to operate in GEO.
The launch of the secretive NRO L-70 payload marked not only the end of the line for Delta IV Heavy, but also for the entire Delta marque. The Delta rocket series stretches back to the 1960s, albeit the original LOx/kerosene powered Delta I, II and Delta III showing little resemblance to the LOx/Hydrogen Delta IV, with the heavy version being effectively three Delta IV’s strapped together, with a cryogenic upper stage. The Delta IVH-4050H (upgraded) is actually built by Boeing Expendable Launch vehicles and launched under the colours of the ULA – United Launch Alliance brand, jointly owned by Boeing and Lockheed Martin.
Flight plan of the NRO-L70 mission launch by the last Delta IV Heavy launch. Courtesy: ULA
The Delta IV was the McDonnell Douglas (later Boeing) offering in the US Air Force Evolved Expendable Launch Vehicle (EELV) programme of the 1990s, the aim of which was to provide cheaper and more reliable access to space for US government and military satellites than existing ‘legacy vehicles’ – especially the very expensive heavy lift Titan IV whose launch cost was often over US$1 billion per flight.
After the smallest variant of Delta IV had been dropped by 1999. The remaining Medium and Heavy variants of the Delta IV were based around a Common Booster Core (CBC). The Delta IV Heavy added two additional CBCs as boosters to provide a shuttle-class launch capability for heavy reconnaissance vehicles. Its launches were only one third the cost of a Titan IV.
However, the Delta IV heavy had an inauspicious start. Its maiden flight, on 21 December 2004, failed because all three CBC engines shut down prematurely, when bubbles in the propellant flow caused the on-board computer to believe it had run dry. In its original and upgraded version, the Delta IV Heavy flew 15 times successfully after that, including this final flight.
The start of the end for Delta IV Heavy
In 2015, ULA announced that the Delta IV Medium would be phased out by 2019 in favour of its less expensive Atlas V stablemate produced by Lockheed Martin. The Delta IV Heavy was retained for heavy government/military payloads (for the US Air Force, National Reconnaissance Office and NASA), mainly because it could lift more than 28 tonnes to a 28.7 degree inclination LEO (from CCAS) and more than 14 tonnes to geostationary transfer orbit (GTO). From 1 March 2019, by order of the 2019 National Defense Authorization Act, the EELV programme became the National Security Space Launch programme in recognition of the availability of both expendable and reusable launch vehicles. However, ULA was already looking forward to its cheaper to operate Vulcan rocket series, whose largest versions will replace the Delta IV Heavy.
The first launch of a new version of the Angara-5
The Russians were taking no chances with the launch of the Angara-5/Orion. The rocket was not carrying a live satellite but was instead to carry an instrumented dummy satellite dubbed the Angara 5 GMM KA mass simulator to check out the launch. The Orion is a new upper stage for the rocket – effectively an upgraded Persei upper stage which itself was a derivative of the venerable Blok DM series.
Angara A5/Orion is launched from Vostochny with a dummy payload aboard. Courtesy: Roscosmos
The Angara A5 is essentially a heavy lift version of the Angara 1.2, using a URM-1 core stage and four URM-1 strap-on boosters. Each URM-1 is powered by an RD-191 engine burning kerosene and liquid oxygen. This first stage is topped by a URM-2 second stage which is 3.6 m in diameter and an upper stage for delivery to orbits beyond LEO. Upper stage options include the Orion, and upgraded version of the Persei, itself a modified Blok DM-03, the Briz-M, or a new cryogenic stage called KVTK, which will use a liquid hydrogen/LOX powered RD-0146D.
After day’s delay caused by the failure of the URM-1 oxidizer tank pressurization system causing a launch cancellation on 9 April, and a second launch scrub the following day, at 0900 GMT on 11 April, the Angara A5/Orion launch vehicle was finally launched. The Angara 5 GMM KA Mass Simulator was successfully launched via a geosynchronous transfer orbit, all the way to a zero inclination geostationary orbit and then to a graveyard orbit above GEO. Before the injection to GTO had taken place, a small 3U-cubesat called Gagarinets was released in the low Earth parking orbit. Later it became apparent that a second cubesat had also been released.
This was the first launch of the Angara A5, a heavy lift rocket from the Vostochny Cosmodrome (rebuilt Svobodny), launch site (previous Angara 5 launches occurred form Plesetsk in Northern Russia.
Comment by David Todd: The Angara A5 has become a controversial rocket. Russia had the opportunity to compete on the commercial market with a new reduced-stage and thus much lower cost version of its venerable Proton expendable rocket which would have been competitive against the Falcon 9. However, instead of financing this change, the Russian government decided to stick with its more capable – but more expensive to operate – modular expendable Angara series. Perhaps the Russian government knew that its rockets would be frozen out of the commercial launch market anyway given its planned invasion of Ukraine.
Not only has it been delayed, its planned main launch site, the Vostochny Cosmodrome – effectively the rebuilt Svobodny launch site in far eastern Russia – also had a very longwinded development and construction with allegations of serious corruption during the project. Still, at least both are up and running, effectively giving Russia a mainline launch site away from Baikonur (Tyuratam) Kazakhstan.
This article was contributed to by Derek Goddard and referenced the Seradata launch vehicle notes by Mark Williamson
