BENGALURU: The Department of Space (DoS), which has tightened exit rules to stem a “spate of voluntary retirements and resignations” from scientists working on flagship missions, is grappling with a bigger challenge quietly building inside India’s space establishment: a growing manpower crunch.DoS employment data analysed by TOI shows nearly three out of every 10 sanctioned posts remain vacant at the end of 2025-26, the widest staffing gap in at least 25 years. Against a sanctioned strength of 20,269 posts, DoS has only 14,637 employees, leaving 5,632 vacancies and a staffing level of just 72.2%. In fact, the 2025-26 employee strength of 14,637 is lower than 14,847 in 2001-02. A key difference is that the sanctioned posts in 2001-02 was just 16,423, putting the then vacancy rate at under 10%.Vacancy rate has steadily worsened over the past few years, falling from nearly 86% staffing in 2019-20 to just over 72% today, despite Isro taking on its most ambitious phase of missions. That the vacancy problem predates the recent wave of resignations, also puts DoS’ July 14 office memorandum in context. Continuous declineIn 2019-20, DoS had 17,222 employees against a sanctioned strength of 20,039 — a staffing level of nearly 86%. Six years later, the sanctioned strength has remained virtually unchanged, but employee strength has fallen by almost 2,600 to 14,637. Staffing levels have declined every year since 2019-20, touching a low of 71.7% in 2024-25 before inching up marginally in 2025-26.Scientific and technical personnel account for roughly three-fourths of DoS’ workforce. The vacancies therefore disproportionately affect engineers, scientists and technical specialists who design satellites, launch vehicles and deep-space missions.The decline has unfolded during one of the busiest phases in India’s space programme with missions to send humans to space, ambitions of taking them all the way to the Moon and building a space station in the pipeline. Isro also has the burden of meeting strategic demand given that the private sector, notwithstanding all the buzz and hype, remains very nascent. On the rocket side, Isro is working on the Next Generation Launch Vehicle (NGLV), a partially reusable vehicle, while plans for a second Mars mission and first Venus missions are also on the drawing board.Covid-19 & reforms impactA recent Parliamentary dealt with the issue of current vacancies and “inquired regarding the reasons for the significant shortage of human resources and measures taken to address the issue”.In its response, DoS said: “…The accumulation of vacancies is largely the result of cascading effects since 2020–21 arising from Covid-19 restrictions, the implementation of sectoral reforms, and the adoption of more stringent and foolproof recruitment procedures.” According to DoS, recruitment processes could only be re-initiated after Oct 2023, which created a substantial gap in recruitment activities for nearly 2-3 years.“Recruitment has already been initiated for 1,449 posts, expected to be completed by Oct 2026, while another 933 posts are slated to be filled by Dec 2026. The remaining vacancies include erstwhile Group D posts and positions that will be filled after implementation of the second cadre review,” as per DoS.The numbers suggest DoS faces two parallel challenges: rebuilding a workforce that has steadily declined over the past few years while retaining experienced scientists working on missions that cannot easily afford to lose institutional knowledge.