ICON resets for October launch from the East Coast

by Chris Bergin

The Pegasus launch of NASA’s Ionospheric Connection Explorer (ICON) satellite is now set to take place on October 6. The launch has also been switched from the West to East coast for the realigned attempt after an issue was noticed during its ferry flight back in June.

ICON is designed to study the frontier of space – the dynamic zone high in Earth’s atmosphere where terrestrial weather from below meets space weather above. The spacecraft will help determine the physics of Earth’s space environment and pave the way for mitigating its effects on our technology and communications systems.

ICON’s findings will help determine the physics of the space environment and pave the way for mitigating its effects on our technology, communications systems and society.

ICON – based on the LEOStar-2 platform – will fly in an orbit around Earth at a 27-degree inclination and at an altitude of some 360 miles. This places it in position for its four instruments to study the ionosphere around the equator. ICON will aim its instruments for a view of what’s happening at the lowest boundary of space at about 55 miles up to 360 miles.

The pre-mission flow for ICON was proceeding along a nominal path at the Vandenberg Air Force Base in California, with the ICON spacecraft encapsulated inside the Pegasus rocket’s fairing and attached to Northrop Grumman’s L-1011 Stargazer aircraft ahead of being ferried to the Reagan Test Site on Kwajalein Atoll.

Pegasus ahead of the ferry flight – by Jack Beyer for NSF/L2

The Pegasus-XL is one of three versions of the Pegasus; alongside the original standard Pegasus, and the Pegasus-H or Hybrid – which used the standard first and second stages, but with the tail modifications to allow launch from Northup Grumman’s own carrier aircraft. The standard Pegasus made six flights between 1990 and 1994, while the Pegasus-H was used for four missions between 1995 and 2000.

Stargazer, which first flew in February 1974, was owned and operated by Air Canada – aside from a brief lease to Sri Lankan carrier Air Lanka in 1982 – as a TriStar passenger airliner until its acquisition by Orbital Sciences Corporation – as they were initially called – in May 1992.

It was during the Stargazer ferry flight with Pegasus that an issue was spotted.

Engineers checking data onboard the Stargazer – via Northup Grumman.

With the vehicle powered up periodically for health checks during the ferry, an anomalous piece of data related to rudder position was recorded.

That led to a deeper analysis and, in the end, a decision to not accept the risk of continuing on with the mission. The problem could not be fixed at the Reagan Test Site, so the pairing returned to Vandenberg for repairs.

Based on apparent range requirements and availability, the realigned launch of the ICON mission won’t see the duo return to the Reagan Test Site.

Instead, the launch – which is now scheduled for NET (No Earlier Than) October 6 – will take place from the East Coast.

As such, Stargazer and Pegasus will use the Skid Strip – Runway 13/31 – at Cape Canaveral Air Force Station (CCAFS) as their take-off point.

The duo will now head to the East Coast – photo by Jack Beyer for NSF/L2

The Shuttle Landing Facility (SLF) at the Kennedy Space Center (KSC) is not set up as a “hot pad” designed to support the L1011 power requirements.

Once launched, ICON will team up with NASA’s Global-scale Observations of the Limb and Disk, or GOLD, mission – which was launched – in a rather interesting fashion by an Ariane 5 ECA – at the start of the year with the SES-14 spacecraft.

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