Delta II

Last updated

N2O4 . These propellants are highly toxic and corrosive, and once loaded the launch had to occur within approximately 37 days or the stage would have to be refurbished or replaced. [29] This stage also contained a combined inertial platform and guidance system that controlled all flight events. [3]

The Delta-K consisted of stainless steel tanks and a lightweight aluminum structure. The tanks were pressurized with helium gas, and the stage featured nitrogen thrusters for roll control during burns and for complete attitude control during coasts. The stage had a mass of 950 kg (2,090 lb) when empty, and 6,954 kg (15,331 lb) when fully fueled. [4]

Third stage

For low Earth orbit missions, Delta II was not equipped with a third stage. Payloads bound for higher energy orbits such as GTO or to reach Earth escape velocity for trans-Mars injection or other destinations beyond Earth used an HTPB solid propellant third stage, situated inside the fairing during launch. This stage was spin-stabilized and depended on the second stage for proper orientation prior to stage separation, but was sometimes equipped with a hydrazine nutation control system to maintain proper spin axis. [27] The third stage would be spun up using small rocket motors and then released by the second stage to perform its burn. The third stage also included a yo-weight system to induce tumbling in the stage after payload separation to prevent recontact, or a yo-yo de-spin mechanism to slow the rotation before payload release. [27] The stage would also contain an S-band transmitter, batteries, and a sequencer to command the stage events.

Two third-stage options were available, both consisting of a single solid rocket motor. The most common by far was Star 48, flying on over 70 missions. The Star 48, also referred to as the Payload Assist Module-Delta (PAM-D, PAM-Delta), was the more, powerful of the two options, producing an average thrust of about 66.4 kN (14,900 lbf) during its 87.1 seconds of burn time. The stage would end up flying primarily on the more powerful Delta variants and never flew on the three-booster configuration.

The other third-stage option was Star 37FM. This stage flew four times, and only on three- and four-booster configurations of Delta. Star 37FM produced about 45.8 kN (10,300 lbf) of thrust during its 66.4-second burn. [4]

Naming system

The Delta II family used a four-digit system to generate its technical names: [30]

For example, a Delta 7925H-10L used the RS-27A, nine GEM 46 boosters, a PAM third stage, and a lengthened 10 ft (3.0 m) diameter fairing. A Delta 6320–9.5 is a two-stage vehicle with an RS-27 first-stage engine, three Castor 4A boosters, a 9.5 ft (2.9 m) diameter fairing, and no third stage.

Launch profile

Launch vehicle build-up
A Delta II launch vehicle was assembled vertically on the launch pad. Assembly started by hoisting the first stage into position. The solid rocket boosters were then hoisted into position and mated with the first stage. Launch vehicle build-up then continued with the second stage being hoisted atop the first stage. [32]
Fueling
It took approximately 20 minutes to load the first stage with 37,900 L (10,000 U.S. gal) of fuel. [33]
At T-45 minutes, fueling completion was confirmed. At T-20 minutes, the FTS pyros were armed. At T-20 minutes and T-4 minutes, two built-in holds occurred. During these holds, final launch checkouts were performed. At T-11 seconds SRB igniters were armed. Ignition of the main engine was at T-0.4 seconds. The ascent profile varies between missions.
SRB staging
If nine solid rocket boosters were used, only six were ignited at launch. After about a minute, once the first six were depleted, three air-start motors would ignite for another minute and the ground-start motors would separate. [34] The air-start motors had nozzles optimized for high-altitude as they operated mostly in a near-vacuum during the flight.
If only three or four boosters were used, all were ignited on the ground and jettisoned at the same time.

Delta II launches

Delta II lifting off with MER-A on 10 June 2003 Lancement Spirit fusee Delta IIs 10062003.jpg
Delta II lifting off with MER-A on 10 June 2003
Delta II Heavy (7925H-9.5) lifting off from pad 17-B carrying MER-B Mer-b-final-launch.jpg
Delta II Heavy (7925H-9.5) lifting off from pad 17-B carrying MER-B

Notable payloads

Earth-orbiting

Interplanetary

The last Delta II launch was the ICESat-2 satellite in September 2018. [31] [35] [36]

In 2008, ULA indicated that it had "around half a dozen" unsold Delta II rockets on hand, [37] and by October 2017, ULA CEO Tory Bruno stated that there were no complete Delta II rockets left in ULA inventory.

There were some unused Delta II components, but not enough to build another vehicle. [38] A Delta II, made of these leftover parts alongside some simulated parts, is located at the Kennedy Space Center rocket garden. [39]

Comparable rockets

Space debris (a.k.a. "Space junk")

The only person on record ever hit by space debris, Mrs. Lottie Williams, was hit by a small, light piece of a Delta II rocket. Mrs. Williams was exercising in a park in Tulsa, Oklahoma on 22 January 1997 when she was hit in the shoulder by a 15-centimeter (6 in) piece of blackened metallic material. The U.S. Space Command confirmed that a used Delta II rocket from the April 1996 launch of the Midcourse Space Experiment had crashed into the atmosphere 30 minutes earlier. The object tapped her on the shoulder and fell off harmlessly onto the ground. Williams collected the item and NASA tests later showed that the fragment was consistent with the materials of the rocket, and Nicholas Johnson, the agency's chief scientist for orbital debris, believes that she was, indeed hit by a piece of a recently launched Delta II. [40] [41]

Delta rockets have been involved in multiple fragmentation events as they were routinely left in orbit with enough fuel to explode. A large amount of current "space junk" is Delta rocket debris. [42]

See also

Notes

  1. (7920-10 model)

References

  1. "Delta II 7920H-10". Archived from the original on 14 July 2014. Retrieved 13 August 2024.
  2. "The Annual Compendium of Commercial Space Transportation: 2018" (PDF). Federal Aviation Administration's Office of Commercial Space Transportation. Bryce Space and Technology. January 2018. Retrieved 13 August 2024.PD-icon.svg This article incorporates text from this source, which is in the public domain.
  3. 1 2 3 4 5 6 Kyle, Ed. "Delta II Data Sheet". spacelaunchreport.com. Archived from the original on 28 July 2014. Retrieved 28 July 2014.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Isakowitz, Steven J.; Hopkins, Joshua B.; Hopkins, Joseph R. Jr. (2004). International Reference Guide to Space Launch Systems (Report) (Fourth ed.). American Institute of Aeronautics and Astronautics.
  5. 1 2 3 Wade, Mark. "Castor 4A engine". Encyclopedia Astronautica. Archived from the original on 20 December 2022. Retrieved 27 February 2024.
  6. "Boeing: Integrated Defense Systems – Delta – Delta II Launch Vehicle Family". Archived from the original on 3 November 2006. Retrieved 13 August 2024.
  7. Dawson, Virginia P.; Bowles, Mark D. (2004). Taming Liquid Hydrogen - The Centaur Upper Stage Rocket (1958-2002) (PDF). NASA. p. 308. Retrieved 13 August 2024.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  8. Rosenthal, Harry F. (16 August 1986). "Reagan Orders NASA To Halt Launch of Commercial Payloads". Associated Press News Archive. Archived from the original on 6 March 2014. Retrieved 13 August 2024.
  9. 1 2 Rumerman, Judy A. (2009). NASA Historical Data Book, Vol. VII: NASA Launch Systems, Space Transportation, Human Spaceflight, and Space Science, 1989–1998 (PDF). NASA. pp. 49–51 (73–75). NASA SP-4012. Retrieved 13 August 2024.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  10. "Delta II, Atlas II, and Atlas III". Los Angeles Air Force Base. 26 April 2013. Archived (PDF) from the original on 14 April 2016. Retrieved 13 August 2024.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  11. McDowell, Jonathan. "Launch Log". Jonathan's Space Report. Archived from the original on 13 November 2009. Retrieved 13 August 2024.
  12. Graham, William (2 July 2014). "ULA Delta II successfully lofts OCO-2 to orbit". nasaspaceflight.com. Retrieved 13 August 2024.
  13. "Delta III Data Sheet". spacelaunchreport.com. Space Launch Report. 2 November 2014. Retrieved 13 August 2024.
  14. Cleary, Mark. "Delta II and III Space Operations at Cape Canaveral 1989–2009" (PDF). afspacemuseum.org. Archived (PDF) from the original on 30 May 2015. Retrieved 13 August 2024.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  15. "United Launch Alliance Joint Venture Completes First Launch - ULA Demonstrates Commitment to Mission Assurance With Delta II West Coast Liftoff for NRO Customer". ulalaunch.com. 14 December 2006. Retrieved 13 August 2024.
  16. "The Hangar/Delta II". spaceflightinsider.com. Archived from the original on 17 November 2017. Retrieved 13 August 2024.
  17. "NASA Selects Launch Services Contract for Three Missions". NASA. 16 July 2012. Archived from the original on 10 May 2013. Retrieved 13 August 2024.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  18. Krebs, Gunter Dirk (14 January 2023). "Koreasat 1, 2 (Mugungwha 1, 2) / Europe*Star B / ABS-1A" . Retrieved 13 August 2024.
  19. "Science & Health Archives". gizmodo.com.au. Archived from the original on 12 February 2009. Retrieved 13 August 2024.
  20. "Unmanned rocket explodes after liftoff". cnn.com. 17 January 1997. Archived from the original on 23 April 2009. Retrieved 14 August 2024.
  21. "DigitalGlobe Successfully Launches Worldview-1". DigitalGlobe. Archived from the original on 2 March 2009. Retrieved 3 March 2009.
  22. "Ariane 5's impressive 75 in-a-row launch record". SpaceDaily. Archived from the original on 1 December 2017. Retrieved 14 August 2024.
  23. "Leftover Delta 2 rocket to go on display at Kennedy Space Center". spaceflightnow.com. Spaceflight Now. 15 September 2018. Archived from the original on 29 January 2019. Retrieved 14 August 2024.
  24. "Space Launch Report". spacelaunchreport.com. Archived from the original on 18 April 2012. Retrieved 14 August 2024.
  25. "RS-27". astronautix.com. Retrieved 14 August 2024.
  26. "RS-27A". astronautix.com. Retrieved 14 August 2024.
  27. 1 2 3 4 "Delta II Payload Planner's Guide 2007" (PDF). ulalaunch.com. Archived (PDF) from the original on 19 September 2011. Retrieved 24 July 2014.
  28. Wade, Mark. "GEM 40". Encyclopedia Astronautica. Archived from the original on 23 December 2022. Retrieved 27 February 2024.
  29. Dr. Marc D. Rayman (15 July 2007). "DAWN Journal". JPL NASA. Archived from the original on 12 October 2008. Retrieved 6 September 2008.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  30. Forsyth, Kevin S. (10 August 2007). "Vehicle Description and Designations". History of the Delta Launch Vehicle. Archived from the original on 8 August 2011. Retrieved 15 March 2008.
  31. 1 2 Graham, William (2 July 2014). "ULA Delta II successfully lofts OCO-2 to orbit". NASASpaceflight.com. Archived from the original on 14 July 2014. Retrieved 23 July 2014.
  32. "Expendable Launch Vehicle Status Report". NASA. 6 June 2007. Archived from the original on 8 June 2007. Retrieved 8 June 2007.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  33. "Swift Launch Pad Activities". 18 November 2004. Archived from the original on 8 August 2007. Retrieved 20 December 2007.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  34. Squyres, Steve (2005). Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet. Hachette Books. ISBN   9781401308513.
  35. "NASA Selects Launch Services Contract For Three Missions". MarketWatch. 16 July 2012. Archived from the original on 29 January 2013. Retrieved 16 July 2012.
  36. "NASA Selects Launch Services for ICESat-2 Mission". NASA Kennedy Space Center. 22 February 2013. Archived from the original on 8 July 2013. Retrieved 15 March 2013.
  37. Berger, Brian (30 June 2008). "Delta 2 Rockets to Remain Competitive Until 2015". Space News. Archived from the original on 3 July 2008. Retrieved 3 July 2008.
  38. @torybruno (17 October 2017). "Less than 1. Last 2 complete DIIs are ordered, JPSS is flying next. Most of a 3rd DII's parts remain in inventory" (Tweet). Retrieved 7 August 2019 via Twitter.
  39. Robert Z. Pearlman (23 March 2021). "Last Delta II takes root in Kennedy Space Center rocket garden". Space.com. Retrieved 11 March 2023.
  40. "Space Junk Survivor". 3 March 2017. Archived from the original on 3 January 2018. Retrieved 2 January 2018.
  41. Long, Tony (22 January 1997). "January 22, 1997: Heads Up, Lottie! It's Space Junk!". Archived from the original on 2 January 2018. Retrieved 2 January 2018.
  42. "Micrometeoroids and Orbital Debris (MMOD)". 14 June 2016. Retrieved 20 March 2023.

Commons-logo.svg Media related to Delta II at Wikimedia Commons

Delta II
Delta II logo.svg
Delta II Dawn liftoff 1.jpg
A Delta II rocket launches from Cape Canaveral carrying the Dawn spacecraft.
Function Launch vehicle
Manufacturer
Country of origin United States
Cost per launch
  • US$51 million in 1987 [a] [1]
  • US$137 million in 2018 [2]
Size
Height38.9 m (128 ft) [3]
Diameter2.44 m (8 ft)
Mass152,000–286,100 kg (335,100–630,700 lb) [3] [4]
Capacity
Payload to LEO
Orbital inclination28.7°
Mass2,776–6,107 kg (6,120–13,464 lb) [4]