The Crew-13 launch to the International Space Station has slipped to no earlier than Sept. 30, 2026, after ground technicians detected a leak of nitrogen tetroxide oxidizer inside the Crew Dragon capsule designated for the mission, NASA confirmed this week.
A Hypergolic Leak Inside the Draco System
SpaceX engineers flagged the issue on or about Aug. 29, 2026, during prelaunch processing of Crew Dragon Grace at Cape Canaveral. The leak involves nitrogen tetroxide (NTO), the oxidizer component of the hypergolic propellant combination that powers the capsule’s Draco thrusters. Hypergolic propellants — monomethylhydrazine (MMH) as fuel paired with NTO as oxidizer — ignite spontaneously on contact, eliminating the need for any ignition hardware and making them a staple of spacecraft reaction control systems.
Each Crew Dragon carries 16 Draco thrusters, each rated at 400 newtons (about 90 pounds of force), arranged around the trunk and service section to handle the precise maneuvers required for ISS approach, departure, and orbital adjustments. The leak was traced to the Draco feed lines, not the more powerful SuperDraco abort thrusters that ring the nose of the capsule.
Echoes of the 2019 SuperDraco Incident
The current fault carries an uncomfortable precedent. In April 2019, an NTO leak past a titanium check valve migrated into a helium pressurization line during a ground test of Crew Dragon’s SuperDraco system, ultimately causing the test capsule to explode and be destroyed. SpaceX’s eventual fix replaced the original movable check valves with pressure-activated burst discs, which contain no moving parts and therefore cannot leak in the same manner.
Although the present leak is isolated to the Draco system rather than the SuperDracos, the response framework is identical: drain all propellant from the affected lines, replace seals and any suspect valves, then pressure-test and recertify the propulsion system before flight. NASA Administrator Jared Isaacman told reporters the turnaround would require “two to four weeks” of repair work, placing the new launch window at NET Sept. 30, 2026, with daily instantaneous launch opportunities available from Space Launch Complex 40.
Crew Dragon Grace’s Second Flight
Grace is the newest and final capsule in SpaceX’s Dragon 2 fleet, and the Crew-13 mission would be its second orbital flight following Axiom Mission 4 in 2025. The hardware assignment was notable because the company had signaled that Grace would absorb some of the flight cadence previously carried by earlier capsules nearing retirement. A propulsion issue on a nearly new vehicle complicates that planning.
The booster assigned to the mission is Falcon 9 Block 5 serial number B1101.3, flying for the third time. SpaceX had already completed a static-fire test of the booster before the oxidizer leak paused integration work on the upper stage.
Meet the Crew-13 Astronauts
Commander Jessica Watkins, a NASA planetary geologist with a PhD from UCLA, will become the first NASA astronaut to fly on a Crew Dragon twice when she launches aboard Grace. Watkins previously flew on SpaceX’s Crew-4 in 2022 and has been publicly outspoken about the value of long-duration ISS science.
Pilot Luke Delaney, a former U.S. Navy aviator, will be making his first spaceflight. The mission’s two mission specialists round out an unusually diverse crew roster: Joshua Kutryk of the Canadian Space Agency, who becomes the first CSA astronaut to launch aboard a SpaceX vehicle after being originally assigned to Boeing’s Starliner; and Sergey Teteryatnikov of Roscosmos, also on his first flight. The four-person crew has remained in quarantine at Johnson Space Center awaiting a new launch date.
Why the Slip Matters for ISS Operations
Even a few weeks of schedule drift carries outsized consequences aboard the ISS, where crew rotation slots are tightly choreographed against cargo arrivals, spacewalks, and visiting vehicle traffic. Expedition crews already aboard the station have sufficient supplies to absorb a launch slip of this magnitude, but ground controllers will have to rebalance handover activities and reschedule any joint operations originally timed to Crew-13’s arrival.
For SpaceX, the incident adds to a year already shaped by hardware scrutiny across its fleet. The fact that the leak surfaced in a Draco line rather than the post-2019 redesigned SuperDraco system is some consolation — the burst disc architecture that solved the earlier failure is still in place elsewhere on the capsule — but every hypergolic leak on a crewed vehicle triggers the same mandatory ground-test and recertification sequence.
Looking Ahead to the Crew-13 Launch
With hardware swaps and pressure testing now underway, SpaceX and NASA are targeting a Crew-13 launch no earlier than Sept. 30, 2026, from SLC-40. If the repair work completes inside Isaacman’s four-week window, the crew could reach the station in early October and begin a six-month science expedition. If additional issues surface during recertification, the mission could push further into the fall and force NASA to reshuffle the downstream Commercial Crew manifest.
For now, the four astronauts of Crew-13 — Watkins, Delaney, Kutryk, and Teteryatnikov — wait for their Dragon to clear the same propellant gauntlet that, in a different capsule and a different propulsion system, destroyed a spacecraft seven years ago. The lessons from that earlier failure now define the path back to the Crew-13 launch pad. The Crew-13 launch now hinges on how fast SpaceX can drain, re-certify, and re-fly Grace without repeating the 2019 mistake.
Source: TechTimes, Sep 14 2026 (https://www.techtimes.com/articles/327512/20260914/crew-13-launch-slips-late-september-after-nto-oxidizer-leak-dragon.htm)